Intraoperative lavage for cytological examination in 1,297 patients with gastric carcinoma

BACKGROUND

This study examined the clinical value of intraoperative peritoneal lavage for cytological examination in patients with gastric cancer. Peritoneal dissemination is the most frequent mode of recurrence for this tumor.

METHODS

A retrospective of lavage findings, other factors, and outcome was performed in 1,297 patients with gastric cancer who underwent intraoperative peritoneal lavage.

RESULTS

The 5-year survival rate of patients with positive lavage cytology was only 2%. Patients who underwent curative resection and had negative cytology had a significantly better 5-year survival rate (P < 0.001). Even among patients with macroscopic peritoneal dissemination, the survival rate was significantly better with negative cytology, which reflected fewer free cancer cells in the peritoneal cavity. Serum concentrations of carcinoembryonic antigen and carbohydrate antigen 19-9 were significantly higher in patients with positive cytology. Multivariate analyses indicated that intraoperative cytological findings was an independent prognostic factor for survival, and was the most important factor for predicting peritoneal recurrence.

CONCLUSIONS

Intraoperative peritoneal lavage cytology is important in predicting survival and peritoneal recurrence in gastric cancer.

Outcome of ratio of lymph node metastasis in gastric carcinoma

BACKGROUND

The purpose of this study was to clarify the outcome of the ratio of the metastatic lymph nodes (RML) in gastric cancer patients.

METHODS

The postoperative survival of 650 patients with gastric cancer who underwent D2 curative gastrectomy was analyzed with regard to the RML. The location, number, and RML in the N1 station and in all (N1 and N2) stations were analyzed. These data were compared from the viewpoints of staging accuracy and patient survival.

RESULTS

The RML was classified as follows: RML 0, no involvement; RML 1, 0 to.1; RML 2,.1 to.25; and RML 3, >or=.25. The 5-year survival rates stratified by RML were RML 0, 86%; RML 1, 68%; RML 2, 35%; and RML 3, 16%. Cox model identified all methods of classifying lymph node metastases as independent prognostic indicators in each calculation. However, a second Cox regression revealed that RML was the only independent prognostic factor among the three methods (P <.001). Stage migration was present in 35 cases (15%) when the number was considered. However, only 15 cases (7%) were underdiagnosed when RML was used.

CONCLUSIONS

RML is a useful classification of patients with gastric cancer. It may prevent the phenomenon of stage migration.

Mapping sentinel nodes in patients with early-stage gastric carcinoma

BACKGROUND

Nodal status in gastric carcinoma is related not only to prognosis but also to the extent of nodal dissection. However, a method for accurate assessment of nodal status during operation has not been established. This study aimed to map the sentinel nodes of gastric carcinoma and to estimate the clinical usefulness of sentinel node biopsy.

METHODS

Following laparotomy, a vital dye (0.2 ml 2 per cent patent blue) was injected through a gastroscope into the submucosal layer at four sites around a clinical T1 gastric carcinoma. The dye immediately appeared at the serosal surface and stained lymphatic vessels and nodes. The stained nodes were removed and examined by frozen sectioning.

RESULTS

The assay was successful in mapping the lymphatic basins in 203 (96.2 per cent) of 211 patients. The dye stained one or more metastatic nodes in 31 patients, but failed to indicate a metastatic node in four patients with a large involved node. Meticulous postoperative examination of all resected nodes in the standard paraffin slices revealed no new metastases. The accuracy of the assay was 98.0 per cent.

CONCLUSION

The method was accurate in predicting nodal status in patients with early-stage gastric carcinoma.

Effects of intraoperative chemohyperthermia in patients with gastric cancer with peritoneal dissemination

BACKGROUND

The most common cause of noncurative resection and recurrence is gastric cancer is peritoneal seeding. However, the results of treatment of peritoneal dissemination with chemotherapy have been poor with 5-year survival rates of 0%.

METHODS

A new in vitro thermochemosensitivity test was performed on gastric cancer cells obtained from 19 surgically resected specimens by using tetrazolium-based colorimetric assay (MTT assay). A novel treatment of the intraoperative chemohyperthermia was undertaken in 83 patients with gastric cancer with peritoneal dissemination. After aggressive resection of primary tumor, lymph nodes, and peritoneal metastases, warmed saline solution containing mitomycin C 30 mg, etoposide 150 mg, and cisplatin 300 mg was introduced into the peritoneal cavity via a closed circuit continuous hyperthermic peritoneal perfusion (CHPP) for 60 minutes to keep the abdominal temperature at 42 degree to 43 degrees C by means of a heat exchange mechanism.

RESULTS

The in vitro thermochemosensitivity test that 43 degrees C enhanced the cytotoxin effects on gastric cancer cells under clinically achievable drug concentrations. During CHPP, drug concentrations of cisplatin, mitomycin C, and etoposide in the perfusate remained statistically higher than in the peripheral venous circulation. Among 43 evaluable patients with residual peritoneal seeding, eight (19%) and nine (21%) exhibited complete response and partial response, respectively. The overall 1- and 5-year survival rates were 43% and 11%, respectively. Patients who underwent complete resection survived significantly longer than those with residual disease, and those with complete response had a significantly better prognosis than did those with partial response, and nonresponders. One-year survival rates with complete response, partial response or nonresponders were 88%, 27% and 22%, respectively. Five patients survived longer than 5 years.

CONCLUSIONS

Our triple treatment combining surgery and CHPP is an effective therapy for selected patients with gastric cancer with peritoneal dissemination.

Hyperthermo-chemotherapy combined with cytoreductive surgery for the treatment of gastric cancer with peritoneal dissemination

Continuous hyperthermic peritoneal perfusion (CHPP) with anticancer agents (mitomycin C and cisplatin) in warm saline was performed in patients with peritoneal dissemination of gastric cancer following resection of the primary lesion. The effect of CHPP was examined by a second-look operation. This study includes 41 cases of gastric cancer with peritoneal dissemination but without liver metastasis treated during the past 6 years. The overall median survival was 14.6 months to 64.2 months from CHPP to death and the 3-year survival rate was 28.5%. Second look surgery revealed a remarkable diminution in the degree of peritoneal dissemination in 7 (50%) of 14 patients with disappearance of ascites after only one course of CHPP in 7 (77.8%) of 9 patients. Long-term 3 year-survival was noted in 4 (9.8%) patients on CHPP. Side effects were renal insufficiency in 2 (5%) patients, leukopenia in 2 (5%) patients, and perforation of the small intestine in 1 (2%) patient. These results suggest the effectiveness of CHPP in the treatment of gastric cancer with peritoneal dissemination.

Expression of c-erbB-2 oncoprotein in gastric carcinoma. Immunoreactivity for c-erbB-2 protein is an independent indicator of poor short-term prognosis in patients with gastric carcinoma

Correlations of c-erbB-2 protein expression with clinical outcomes of gastric carcinomas were studied in 189 gastric carcinomas. There were 23 (12.2%) carcinomas with evidence of c-erbB-2 protein in which the reaction was localized to the cell membrane. There was no significant association between c-erbB-2 staining and the macroscopic or histologic type of the carcinomas. c-erbB-2-stained tumors were more likely to be associated with serosal invasion, nodal involvement, and peritoneal metastasis, than c-erbB-2-unstained ones. In addition, c-erbB-2 was stained in none of early gastric carcinomas. The 5-year survival rates of the c-erbB-2 protein-positive and the protein-negative group were 11% and 50%, respectively. When the c-erbB-2 tissue status and seven clinicopathologic variables as conventional prognostic factors were entered simultaneously into the Cox regression model, serosal invasion, hepatic metastasis, peritoneal metastasis, nodal status, and c-erbB-2 tissue status emerged as independent prognostic variables. The results suggested that c-erbB-2 protein expression might be enhanced in advanced stages during the progression of gastric carcinoma. In this particular group of patients, immunoreactivity for c-erbB-2 protein is an indicator of poor short-term prognosis.

Continuous hyperthermic peritoneal perfusion for the treatment of peritoneal dissemination in gastric cancers and subsequent second-look operation

A total of 31 patients with gastric cancer showing peritoneal dissemination received continuous hyperthermic peritoneal perfusion (CHPP) in combination with the administration of cisplatin (CDDP) and mitomycin C (MMC). The authors developed a new special device named the peritoneal cavity expander (PCE) for sufficient perfusion and direct temperature measurement in the peritoneal cavity. As complications of CHPP three patients presented with bone marrow suppressions (leukocytes less than or equal to 3000/mm3 and/or platelets less than or equal to 30,000/mm3): one, leakage of intestinal anastomosis; one, intestinal perforation; and one, acute renal failure. But none of them was lethal. Twelve of 31 patients who had received CHPP during the initial operation underwent second-look operation (SLO) for the assessing the effects of CHPP and for resecting residual or recurrent tumors. Among 12 patients who received SLO complete response (CR) was observed in four patients, partial response (PR) in one, no change (NC) in three, and progressive disease (PD) in four, with the overall response rates (%CR + %PR) standing at 41%. Two-year survival rate of the complete and partial responders was 50%, which was significantly higher than 0% of the other responders (NC + PD). The survival curves of the two groups were significantly different (P less than 0.05, generalized Wilcoxon test). These results supported that CHPP was well tolerated and effective for the treatment of patients with peritoneal dissemination in gastric cancer when combined with anti-cancer drugs having synergism with hyperthermia. Since the outcome of SLO was one of prognostic factors it was important to follow up these patients by SLO.

Inflammation-induced repression of tumor suppressor miR-7 in gastric tumor cells

Inflammation has an important role in cancer development through various mechanisms. It has been shown that dysregulation of microRNAs (miRNAs) that function as oncogenes or tumor suppressors contributes to tumorigenesis. However, the relationship between inflammation and cancer-related miRNA expression in tumorigenesis has not yet been fully understood. Using K19-C2mE and Gan mouse models that develop gastritis and gastritis-associated tumors, respectively, we found that 21 miRNAs were upregulated, and that 29 miRNAs were downregulated in gastric tumors in an inflammation-dependent manner. Among these miRNAs, the expression of miR-7, a possible tumor suppressor, significantly decreased in both gastritis and gastric tumors. Moreover, the expression of miR-7 in human gastric cancer was inversely correlated with the levels of interleukin-1β and tumor necrosis factor-α, suggesting that miR-7 downregulation is related to the severity of inflammatory responses. In the normal mouse stomach, miR-7 expression was at a basal level in undifferentiated gastric epithelial cells, and was induced during differentiation. Moreover, transfection of a miR-7 precursor into gastric cancer cells suppressed cell proliferation and soft agar colony formation. These results suggest that suppression of miR-7 expression is important for maintaining the undifferentiated status of gastric epithelial cells, and thus contributes to gastric tumorigenesis. Although epigenetic changes were not found in the CpG islands around miR-7-1 of gastritis and gastric tumor cells, we found that activated macrophage-derived small molecule(s) (<3 kDa) are responsible for miR-7 repression in gastric cancer cells. Furthermore, the miR-7 expression level significantly decreased in the inflamed gastric mucosa of Helicobacter-infected mice, whereas it increased in the stomach of germfree K19-C2mE and Gan mice wherein inflammatory responses were suppressed. Taken together, these results indicate that downregulation of tumor suppressor miR-7 is a novel mechanism by which the inflammatory response promotes gastric tumorigenesis.

Amplification of the c-met, c-erbB-2 and epidermal growth factor receptor gene in human gastric cancers: correlation to clinical features

We examined amplification of the c-met, c-erbB-2, and epidermal growth factor receptor (EGFR) gene in the patients with primary gastric cancer, and compared the data with clinical features in order to clarify the relationship between oncogenic abnormality and clinical features. Oncogene amplifications were examined by slot blot hybridization using DNAs extracted from formalin-fixed and paraffin-embedded tissues of primary gastric cancers. Seven of the seventy cancers (10.0%) had c-met gene amplification, nine (12.9%) had c-erbB-2 gene amplification, and six (8.6%) had EGFR gene amplification, respectively. Eighteen cases (25.7%) exhibited one or multiple oncogene amplification, and two cases (2.9%) exhibited simultaneous amplification of the three genes. The cases with c-met gene amplification tend to show invasive character and were related to peritoneal dissemination. The cases with c-erbB-2 gene amplification were related to lymph node metastasis. The cases with EGFR gene amplification had large tumors and were in highly advanced stage. The survival rate in patients with oncogene amplification was significantly lower than that in patients without amplification. Our data indicated that these genes were related to growth and metastasis of gastric cancer. Furthermore, this study about the three genes suggested that the type of activated gene might decide on the type of metastasis and clinical features.

Lymphangiogenesis and the vascular endothelial growth factor receptor (VEGFR)-3 in gastric cancer

Vascular endothelial growth factor C (VEGF-C) is the only factor known to cause lymphangiogenesis. We studied the correlation between VEGF-C and vascular endothelial growth factor receptor-3 (VEGFR-3) expression of 85 primary gastric cancers by reverse transcriptase-polymerase chain reaction (RT-PCR) and immunohistochemistry, and the results were correlated with the number of lymphatic vessels, stained with anti-VEGFR-3 antibody. RT-PCR and immunohistology demonstrated that VEGF-C was mainly produced from cancer cells, but not from stromal elements. Morphologically, VEGFR-3 expression was detected in the endothelial cells of the stromal lymphatic vessels. There was a statistically positive correlation between the incidence of VEGF-C and VEGFR-3 mRNA expression in the primary tumours (P=0.0002). The number of VEGFR-3-positive lymphatic vessels in VEGF-C mRNA positive tumours was significantly larger than that in VEGF-C-negative tumours. The number of VEGFR-3-positive vessels in the tumour stroma was closely related to the grade of lymphatic invasion of gastric cancer. These results strongly indicate that VEGF-C may induce the proliferation of lymphatic vessels in the stroma of primary gastric cancer via activation of VEGFR-3, expressed on the endothelial cells of lymphatic vessels. In these circumstances, cancer cells can easily invade the lymphatic vessel, because of the increase of the contact points of cancer cells with the lymphatic vessels.

Expression of p53 protein in colorectal cancer and its relationship to short-term prognosis

BACKGROUND AND METHODS

The expression of p53 protein in 100 large bowel cancers was studied immunohistochemically by use of a monoclonal antibody (PAb1801).

RESULTS

Immunoreactivity was found in 61.0% of specimens from 100 patients with colorectal cancer. The pattern of p53 expression was mainly detected in the nuclei of the cancer cells. There was no significant correlation between the expression of p53 and the histologic grade, tumor size, serosal invasion, lymphatic invasion, venous invasion, lymph node metastasis, or liver metastasis. However, patients with p53-positive tumors had a greater relative risk of death compared with those with p53-negative tumors. The p53 negative-tumors showed a recurrence rate of 5.9%; for the p53 positive-tumors, a recurrence rate of 23.8% was recorded. The 3-year survival rate was 96.7% of 39 patients with p53-negative carcinomas and 61.8% for the patients with p53-positive tumors; there was a significant difference in the rate between the two groups of patients (P < 0.05). The growth fraction of p53-positive tumors determined with a monoclonal antibody against DNA polymerase alpha (49.0%) was significantly higher than that of p53-negative tumors (40.7%, P < 0.01).

CONCLUSIONS

These results suggest that the immunoreactivity of p53 may be a biologic marker of prognostic significance.

Neoadjuvant chemotherapy for high-grade advanced gastric cancer

Fifty-five patients with high-grade advanced gastric cancer in whom the presence of stage IV was confirmed by preoperative diagnostic imaging were treated with PMUE therapy by a combined use of cisplatin (CDDP) 75 mg/m2, mitomycin C (MMC) 10 mg/body, etoposide 150 mg/body, and UFT (a combination of 1-(2-tetrahydrofuryl)-5-fluorouracil and uracil in a molar ratio of 1:4) 400 mg/day. CDDP and MMC was administered intravenously on the first day, followed by etoposide 50 mg/day on the 3rd, 4th, and 5th days. All the patients had measurable lesions that were evaluated by computed tomography scanning before and after the treatments. These patients were allocated randomly to two groups. Of these cases, 29 belonged to the neoadjuvant chemotherapy (NAC) group to whom PMUE therapy was given preoperatively; the remaining 26 patients underwent operation first and received PMUE thereafter (control group). Background factors did not differ significantly between the two groups. The response rate was higher in the NAC group than in the control group (62% in the former versus 35% in the latter). The resectability rates were 79% and 88% in the NAC and control groups, respectively. However, the rate of potentially curable cases was higher in the NAC group than in the control group (38% in the former versus 15% in the latter). Among the nonresection cases, the prognosis was highly unfavorable in both groups. In the resection cases, however, the survival rate was significantly better in the NAC group than in the control group. These results may indicate that in patients with high-grade, advanced gastric cancer initial chemotherapy (neoadjuvant chemotherapy) and then surgery should be considered.

Bafilomycin A1 induces apoptosis in the human pancreatic cancer cell line Capan-1

Bafilomycin A1, a specific inhibitor of vacuolar type H(+)-ATPase, can inhibit the growth of a variety of cultured cells in a dose-dependent manner, but its mechanism is unclear. The aim of this study was to examine whether bafilomycin A1 inhibits the growth of Capan-1 human pancreatic cancer cells through apoptosis. The effect of bafilomycin A1 on tumour growth in vitro and in vivo was examined using an MTT assay and an in vivo tumour model. The presence or absence of apoptosis was determined by morphology and DNA analysis of tumour cells. The concentration of bafilomycin A1 for 50 per cent inhibition of cell viability during 72 h by the MTT assay was 5 nm. In DNA analysis, a ladder of fragmented DNA was detected in Capan-1 cells treated with bafilomycin A1 at concentrations greater than 10 nm for 24 h. Nude mice bearing a xenografted Capan-1 cell line tumour received 4 weeks of bafilomycin A1 (1.0 mg/kg per day). This treatment significantly inhibited tumour growth compared with controls after 21 days (P < 0.05). Histopathological examination of tumour cells in the treated group demonstrated signs of apoptosis with chromatin condensation and cell shrinkage. These observations suggest that bafilomycin A1 inhibits the growth of Capan-1 human pancreatic cancer cells through apoptosis.

Diagnostic laparoscopy, serum CA125, and peritoneal metastasis in gastric cancer

BACKGROUND AND STUDY AIMS

Peritoneal metastasis is a crucial factor for the prognosis in gastric cancer, but its diagnosis is difficult before laparotomy. We report on the utility of laparoscopy and its indications in the detection of peritoneal metastasis in gastric cancer.

PATIENTS AND METHODS

A total of 39 patients with gastric cancer underwent laparoscopy and peritoneal cytology investigation in our department, between April 1992 and April 2000. Laparoscopic diagnosis for peritoneal metastasis (LP-P) was determined through macroscopic, pathological and cytological diagnoses. All the patients underwent diagnostic imaging with computed tomography (CT) and ultrasound before laparoscopy. Carcinoembryonic antigen, carbohydrate antigen (CA) 19-9, and CA125 levels in serum and peritoneal fluid were measured using enzyme immunoassay.

RESULTS

Laparoscopic diagnosis for peritoneal metastasis gave negative results in 21 patients and positive results in 18. All the patients with negative LP-P findings underwent surgery; 18 of the 21 patients showed no peritoneal metastasis, but three were diagnosed as having peritoneal metastasis, one at the pouch of Douglas and two at the mesentery. The diagnosis of all the patients with positive LP-P findings was finally confirmed as correct. The specificity, sensitivity, and accuracy of laparoscopy for peritoneal metastasis were 100 % (18/18, 95 % CI 0.82 - 1), 86 % (18/21, 95 % CI 0.64 - 0.97), and 92 % (36/39, 95 % CI 0.79 - 0.98), respectively. The specificity, sensitivity, and accuracy of diagnostic imaging for peritoneal metastasis were 100 % (18/18, 95 % CI 0.82 - 1), 38 % (8/21, 95 % CI 0.18 - 0.62), and 67 % (26/39, 95 % CI 0.50 - 0.81), respectively. All of the 11 patients showing high levels of serum CA125 (equal to or more than 35 U/ml) had peritoneal metastasis whereas 17 of the 26 patients with low levels of serum CA125 (less than 35 U/ml) did not ( P < 0.001).

CONCLUSIONS

The sensitivity of laparoscopy for peritoneal metastasis was much higher than that of diagnostic imaging. Laparoscopy and serum CA125 level both predicted peritoneal metastasis, but the degree, volume, or distribution of peritoneal metastasis was disclosed only by laparoscopy. Laparoscopy is a useful way of detecting peritoneal metastasis in gastric cancer, and patients with an elevated level of serum CA125 are the best candidates for laparoscopy.

Impact of the biliary diversion procedure on carcinogenesis in Barrett's esophagus surgically induced by duodenoesophageal reflux in rats

OBJECTIVE

To determine whether the elimination of bile reflux in the established esophagojejunostomy model of Barrett's esophagus (BE) will reduce or eliminate the risk of developing esophageal adenocarcinoma.

SUMMARY BACKGROUND DATA

Reflux of duodenal juice as well as gastric acid plays an important role in the pathogenesis of BE and adenocarcinoma. Duodenoesophageal reflux (DER) per se induces these diseases without carcinogen. However, it is unclear whether antireflux surgery induces regression of BE and prevents adenocarcinoma.

METHODS

Two hundred F344 male rats underwent one of following 3 operations: (1) total gastrectomy and esophagojejunostomy to induce DER, followed by killing after 20 (n = 13), 30 (n = 12), and 50 weeks (n = 30); (2) biliary diversion procedure, converted to Roux-en-Y method, to avoid bile regurgitation into the esophagus at 20 (n = 29) and 30 weeks (n = 32) after the operation to induce DER, followed by killing 50 weeks after initial operation; or (3) total gastrectomy and Roux-en-Y esophagojejunostomy followed by killing after 50 weeks served as controls (n = 28).

RESULTS

BE developed in more than half of the animals exposed to DER for 20 weeks, in more than 90% of rats with DER for 30 weeks, and in 100% of animals exposed to DER for 50 weeks. In the incidence and the length of BE, there is no difference between the animals that underwent biliary diversion at 20 (62%) and 30 weeks (94%) and those that had DER for 20 (54%) and 30 weeks (92%), respectively. Incidence of adenocarcinoma was significantly lower in the rats that underwent the biliary diversion procedure after 30 (19%) and 20 weeks (3%) than in the rats that had DER for 50 weeks (60%) (P < 0.005). None of the control animals that underwent Roux-en-Y esophagojejunostomy developed BE and carcinoma.

CONCLUSIONS

It is likely that the converting procedure from the esophagojejunostomy to induce DER to biliary diversion does not lead to regression of BE but prevents the development of esophageal adenocarcinoma in the rats.

PTD classification: proposal for a new classification of gastric cancer location based on physiological lymphatic flow

BACKGROUND

We propose a new classification for the location of gastric cancer - the PTD classification (i.e., zones P, T, and D; see below), with the zones classified according to the physiological lymphatic flow.

METHODS

Three hundred and thirty-six patients with T1 or small T2 gastric cancer who underwent sentinel node mapping at our hospital were enrolled. The relationship between the location of the gastric cancer and the physiological lymphatic flow derived from sentinel node mapping was investigated. Lymphatic basins were defined as lymphatic zones divided by the stream of stained lymphatic canals.

RESULTS

One hundred and forty-six patients underwent standard gastrectomy with more than D2 dissection and the other 190 patients underwent function-preserving gastrectomy with the omission of lymph node dissection outside the lymphatic basin. In the former group, the progression pattern of lymph node metastasis was observed; nodal metastasis occurred in sentinel nodes first, and rarely extended outside the lymphatic basin. In the latter group, none of the patients have had a recurrence. The PTD classification we propose is as follows: the dividing line between the proximal region (zone P) and the transitional region (zone T) is the line that links the point of the watershed between the left gastroepiploic artery and right gastroepiploic artery, to the point that is the inflow point of the first descending branch of the left gastric artery; and the dividing line between zone T and the distal region (zone D) is an arc at a radius of 8 cm from the pylorus. There were no lymphatic basins within the right gastric artery area for tumors located in zone T.

CONCLUSION

The advantage of the PTD classification is that if the PTD classification were to be used as a guide for gastric resection procedures, preservation of the pylorus would become possible without diminishing the prognosis in patients with cT1N0 cancer located in zone T.

Inverse association of nm23-H1 expression by colorectal cancer with liver metastasis

The expression of nm23-H1 mRNA and protein was studied in colorectal cancers by Northern blotting and immunohistochemistry. All 21 colorectal cancers studied by Northern blotting had increased levels of nm23-H1 mRNA relative to the adjacent normal colonic mucosa. Increased nm23-H1 protein expression was also observed in all 36 colorectal cancer cases including those studied by Northern blotting. There was no significant correlation between nm23-H1 expression and tumour histology, serosal invasion, lymphatic invasion, venous invasion, or lymph node metastasis. However, the expression of both mRNA and protein was significantly lower in tumours associated with liver metastasis than in those without such metastasis. These observations indicate that the nm23 gene may play a role in the suppression of liver metastasis of colorectal cancer.

Angiotensin II enhances epithelial-to-mesenchymal transition through the interaction between activated hepatic stellate cells and the stromal cell-derived factor-1/CXCR4 axis in intrahepatic cholangiocarcinoma

We previously reported that hepatic stellate cells (HSCs) activated by angiotensin II (AngII) facilitate stromal fibrosis and tumor progression in intrahepatic cholangiocarcinoma (ICC). AngII has been known as a growth factor which can promote epithelial-to-mesenchymal transition (EMT) in renal epithelial cells, alveolar epithelial cells and peritoneal mesothelial cells. However, in the past, the relationship between AngII and stromal cell-derived factor-1 (SDF-1) in the microenvironment around cancer and the role of AngII on EMT of cancer cells has not been reported in detail. SDF-1 and its specific receptor, CXCR4, are now receiving attention as a mechanism of cell progression and metastasis. In this study, we examined whether activated HSCs promote tumor fibrogenesis, tumor progression and distant metastasis by mediating EMT via the AngII/AngII type 1 receptor (AT-1) and the SDF-1/CXCR4 axis. Two human ICC cell lines and a human HSC line, LI-90, express CXCR4. Significantly higher concentration of SDF-1α was released into the supernatant of LI-90 cells to which AngII had been added. SDF-1α increased the proliferative activity of HSCs and enhanced the activation of HSCs as a growth factor. Furthermore, addition of SDF-1α and AngII enhanced the increase of the migratory capability and vimentin expression, reduced E-cadherin expression, and translocated the expression of β-catenin into the nucleus and cytoplasm in ICC cells. Co-culture with HSCs also enhanced the migratory capability of ICC cells. These findings suggest that SDF-1α, released from activated HSCs and AngII, play important roles in cancer progression, tumor fibrogenesis, and migration in autocrine and paracrine fashion by mediating EMT. Our mechanistic findings may provide pivotal insights into the molecular mechanism of the AngII and SDF-1α-initiated signaling pathway that regulates fibrogenesis in cancerous stroma, tumor progression and meta-stasis of tumor cells expressing AT-1 and CXCR4.

A COX-2 inhibitor prevents the esophageal inflammation-metaplasia-adenocarcinoma sequence in rats

Barrett's esophagus (BE) and esophageal adenocarcinoma (ADC) is associated with reflux of duodenal contents. Cyclooxygenase (COX)-2 is over-expressed in BE and ADC, and supposedly contributes to esophageal carcinogenesis. The aim of this study is to investigate what effect a COX-2 inhibitor has on esophageal adenocarcinogenesis in rats. A series of 90 rats underwent a duodenoesophageal reflux procedure and were divided into 2 groups. One group was given commercial chow (control group), and the other was given experimental chow containing celecoxib (celecoxib group). The animals were sacrificed sequentially, at the 10th, 20th, 30th and, finally, 40th week after surgery, and their esophagi were examined. In the control group, esophagitis, columnar-lined epithelium (CLE) and ADC were first observed at the 10th week, 20th week and 30th week, respectively. Their incidences sequentially increased and at the 40th week reached 100, 89 and 47%, respectively. In the celecoxib group, the esophagitis was mild and the incidence of CLE was significantly lower at each week (P < 0.001), compared with the control group, and ADC was not observed throughout the experiment (P < 0.05). COX-2 expression was observed predominantly in the stroma of inflamed esophageal epithelia, and up-regulated at the 10th and 20th week (P < 0.05, respectively). PGE2 level and proliferative activity were also up-regulated in both groups, but they were lower in the celecoxib group than in the control group (P < 0.05). Apoptosis was observed to increase with celecoxib treatment (P < 0.05). Celecoxib is effective in preventing CLE and ADC by suppressing esophagitis in rats.

Interrelationship between transforming growth factor-alpha and epidermal growth factor receptor in advanced gastric cancer

An immunohistochemical study for transforming growth factor-alpha (TGF alpha) and epidermal growth factor receptor (EGFR) was made with 167 primary tumors of advanced gastric cancer to demonstrate the potential existence of autocrine mechanism. TGF alpha stained positively in 87 (52%), and EGFR in 68 (41%) of the tumors. The authors classified the tumors into the following three groups: group 1 with neither TGF alpha nor EGFR staining positively (63 tumors); group 2 with either TGF alpha or EGFR staining positively (53 tumors); group 3 with both TGF alpha and EGFR staining positively (51 tumors). The incidence rates of macroscopically infiltrative tumors and large tumor measuring 6 cm or more in diameter were significantly higher for group 3 than for groups 1 and 2. The patients of group 3 had the poorest prognosis, with a 5-year survival rate of only 12%, while the 5-year survival rates were 45 and 36% for groups 1 and 2. There was a significant difference in survival between the patients of group 1 and those of group 3. Bromodeoxyuridine labeling indices were significantly higher in the tumors belonging to group 3 (median 15.8%) than in those of group 1 (median 10.8%). The results suggest that the autocrine mechanism between TGF alpha and EGFR may play an important role in the progression of gastric cancer, and that when such a mechanism becomes operative, prognosis may be poor.

A subanalysis of Japanese patients in a randomized, double-blind, placebo-controlled, phase 3 trial of nivolumab for patients with advanced gastric or gastro-esophageal junction cancer refractory to, or intolerant of, at least two previous chemotherapy regimens (ONO-4538-12, ATTRACTION-2)

BACKGROUND

Nivolumab, an anti-programmed death-1 agent, showed survival benefits in Asian patients, including Japanese, with gastric/gastro-esophageal junction (G/GEJ) cancer. We report the analysis of the Japanese subpopulation from ATTRACTION-2 that evaluated nivolumab versus placebo in unresectable advanced or recurrent G/GEJ cancer after ≥ 2 chemotherapy regimens.

METHODS

Data from the Japanese subpopulation in the randomized, double-blind, placebo-controlled, phase 3 trial were analyzed (data cutoff, February 25, 2017). Primary endpoint was overall survival (OS); secondary endpoints included progression-free survival (PFS) and objective response rate (ORR).

RESULTS

Among the overall study population of 493 patients, 226 (nivolumab 152; placebo 74) were enrolled from 28 sites in Japan. In the Japanese subset, median OS was longer with nivolumab versus placebo (5.4 months, 95% CI 4.6-7.4 versus 3.6 months, 95% CI 2.8-5.0). The risk of death was lower in the nivolumab versus placebo group (hazard ratio 0.58, 95% CI 0.42-0.78; p = 0.0002). Incidences of serious adverse events were 23% (35/152) and 25% (18/72) in the nivolumab and placebo groups, respectively. In the Japanese ITT population, 22% of nivolumab-treated and 28% of placebo-treated patients received prior ramucirumab treatment. Overall, clinical activity of nivolumab was observed regardless of prior ramucirumab use. In the nivolumab group, ORR and PFS were numerically higher in patients with prior ramucirumab use than in those without.

CONCLUSIONS

In the Japanese subpopulation, patients receiving nivolumab had longer OS, similar to the overall population, with a manageable safety profile. The interaction between nivolumab and ramucirumab will be clarified in ongoing clinical trials.

Local angiotensin II-generation in human gastric cancer: correlation with tumor progression through the activation of ERK1/2, NF-kappaB and survivin

Angiotensin II is a main effector peptide in renin-angiotensin system, acting as a growth promoter via angiotensin II type 1 (AT1) receptor. The present study examined intrinsic angiotensin II generating system in gastric cancer and potential roles of angiotensin II in cellular proliferation and survival. The expression of AT1 receptor was examined in gastric cancer cell lines and tissues. In addition, we measured angiotensin II concentration in tissues from twenty gastric cancer and corresponding normal region using the florisil method. In vitro, we investigated the potential roles of angiotensin II in cellular proliferation and cell survival in cultured human gastric cancer cell line. The effects of AT1 receptor blocker candesartan were evaluated in a mouse model of peritoneal carcinomatosis. AT1 receptor protein was expressed in gastric cancer cell lines and tissues. Angiotensin II concentration in tumor region (1447+/-624 pg/g wet) was significantly higher than those of normal region (775+/-320 pg/g wet) (p<0.05). Angiotensin II stimulates the cell proliferation in the AT1 receptor-positive OCUM2MD3 gastric cancer cell line and this proliferative effect of angiotensin II was inhibited by a specific AT1 receptor antagonist, candesartan. We also confirmed the angiotensin II stimulated ERK1/2, nuclear transcript factor-kappaB (NF-kappaB) and surviving activation, which are central molecules of cellular proliferation and survival in OCUM2MD3 cells. Candesartan significantly prolonged survival time in a mouse model of peritoneal carcinomatosis compared with control group (p=0.0.197, log-rank test). Our data provide in vivo evidence of intrinsic angiotensin II generating system in gastric cancer and indicate locally formed angiotensin II is involved in cellular proliferation and survival.

Analysis of proliferative activity using anti-proliferating cell nuclear antigen antibody in gastric cancer tissue specimens obtained by endoscopic biopsy

BACKGROUND

Proliferative activities of tumors are thought to be prognostic features of malignant tumors, but their value as measured by proliferating cell nuclear antigen (PCNA) labeling remains unclear in gastric cancer.

METHODS

PCNA labeling rates (LR) were quantified in 121 paraffin-embedded biopsy specimens from primary tumors by immunocytochemistry.

RESULTS

Immunohistochemical analyses have demonstrated that PCNA presents an intense staining in the nuclei of tumor cells and mucous neck cells of gastric glands. The PCNA LR ranged from 12% to 79% (mean +/- standard deviation), and a significant correlation was found between bromodeoxyuridine labeling indices and PCNA LR: PCNA LR were closely associated with tumor size, serosal invasion, and nodal involvement. The patients with tumors with high PCNA LR (greater than 40%) were dead significantly earlier than were those with tumors with low PCNA LR: When the PCNA LR and all the clinicopathologic parameters were entered into a Cox regression model, PCNA LR emerged as an independent prognostic factor.

CONCLUSION

These results indicate that PCNA LR may be a potentially useful prognostic factor for gastric cancer.